Agreed. Anybody who was mildly competent would never arm a common assassin with a Valyrian Steel dagger. That's totally ludicrous. Littlefinger would never do that, Jaime would never do that, Cersei would never do that, etc. A regular dagger can easily do the job without the attention that would be garnered by using a Valyrian Steel dagger (especially one so fancy and distinct). Only a dumbass who picked out the weapon because he thought it looked cool would do that, especially the only dumbass we know who had ready access to that kind of weaponry.

That's NOT a lie. You keep saying that, but you don't seem to understand what constitutes a lie. Operating on an erroneous assumption isn't a lie, it's a mistake. A lie is a willful distortion of the truth. If someone had known straightaway what happened, and said otherwise, then yes, it would be a lie. We have no proof whatsoever that anyone lied at any point, though.
1) Lyanna disappears: Everyone believe Rhaegar abducted her. That was a sincere belief, and seemed the most logical conclusion based off the available evidence at the time. If the people who repeat that story honestly believe it, then no, it's not a lie.
2) Brandon goes to King's Landing: Brandon went to King's Landing on the mistaken assumption that Rhaegar kidnapped and raped Lyanna. Again, if he sincerely believed that, then it wasn't a lie, but an erroneous conclusion.
3) Aerys calls for the heads of Ned Stark and Robert Baratheon: That was something that most assuredly happened, which left them with only two choices, rebel or die. so where's the lie there?
There are a lot of incorrect assumptions, but that's nowhere near the same as the rebelling beginning with a lie.

Likewise. I really wanted it to be Aemon for various reasons. For one, if he does become king, he'd be King Aemon, First of His Name, as no other Aemon's have ever become king. Second, he would've been named for the only other Targaryen Jon's ever known. One who became very important to Jon just as he was very important to Rhaegar, with whom Rhaegar constantly talked to about the Prophecy of the Prince-That-Was-Promised (Which means that Maester Aemon would've been talking about Jon Snow years before his birth).

It made sense to me. After all, the White Walkers have been quiet for thousands of years, and they suddenly appear? If they're marching to the wall, it's because they've got a plan to get past it. Unfortunately for Jon, the logical conclusion ended up helping the White Walkers out, because as it turned out they never had a plan to get past the wall that DIDN'T involve a dragon. Had Daenerys and her dragons stayed south of the wall the White Walkers would've been stuck up there forever.

Yeah, that's very frustrating. So apparently the Night King had no plan the entire time and was kind of sort of just hoping for the best? Complete crap. Bringing down the wall with Viserion, that's something that should've happened after he had another plan which he tried but which he failed thanks to the heroes, but then he gets the dragon and turns the tables on them again. Point is, there should've been a Plan A, and using Viserion should've been an impromptu Plan B that he stumbled onto after the failure of Plan A. But turns out there was never a Plan A the entire time.

She's been portrayed as good for the most part so far, but remember, Aerys was once considered a good king until he went insane, at which point he became the worst villain known in Westeros.
Watching the show, even if Martin goes that route in the books, I'm thinking the showrunners are going to go for a cheaper, safer ending. As for the books, I still think that's likely. Martin has spent way too much time critiquing Lord of the Rings clones just to make his own with its own Dark Lord and everything.
My personal theory is that one of the main inspirations for A Song of Ice and Fire is the scene in Lord of the Rings when Galadriel is tempted by the One Ring. Remember that scene? For a minute there it's terrifying what she's on the cusp of becoming, but then she regains control and doesn't give in to the temptation. In the case of Daenerys, however, I think that's the end goal. A character who starts off like Galadriel, BUT who succumbs to the temptation of the One Ring and goes dark. That, I think is Martin's end goal (And yeah, I very much doubt he'd basically spoil the ending of his 20+ year novel series. Misdirect, yes, but outright spoil?).

I'm really bugged by the Night King's progress towards the Wall, not least of which being: why the hell has it taken so long?
The other big issue is, the Night King had to have had a method by which he intended to get past the Wall. Judging from what we've seen, though, he had nothing. Literally nothing. There is no plan to get past the Wall. In which case, why did he ever even bother getting out of bed? Or was the plan to just mill about north of the Wall until someone flew a dragon north? Was that really the plan? Because if so, that's stupid. But then again, judging from GoT lately, stupid writing seems to be the name of the game lately.
Now, what WOULD make sense is if the Night King had a plan to get past the Wall, almost succeeded, but was stopped at the last moment by Jon and Daenerys. But in the process the Night King kills Viserion, giving him another, unexpected means of getting past the Wall after his original plan failed. Now that would be good storytelling. For instance, I saw a theory that the Night King was waiting for the water along the coast to freeze over, in which case his army could then simply walk around the Wall. That would give the dragons a reason to be there, as they'd torch the frozen waters to drown the Wights and force the rest to retreat back to land. Then the Night King could kill Viserion, and boom, now he'd have a fire-breathing dragon which would give him the option of burning down the Wall instead.
That would've been a lot better than what we did get, which basically amounts to the Night King spending DECADES amassing an army and marching for years all over the Land of Always Winter and Wildling territories, hoping a dragon would drop into his lap so he could finally go south.

They were the only Stark children who never had a real sibling relationship. As soon as Sansa was old enough to be aware of what a bastard was, Jon essentially become non-existent in her world, and she only talked to him when she absolutely had to. They were as close to each other emotionally as neighbors who only exchange small talk on occasion when they cross paths and there's no avoiding it. That's far from anything resembling actual sibling feelings. Personally, I think that was something which Martin did on purpose, have that distance between them which prevented the formation of an actual sibling bond, in order to open the door for this relationship down the road. There's plenty of evidence throughout the novels which hints at this pairing and now in the show, as well, but I've been repeating it all til I turned blue in the face.

IMO, I believe the following will happen:
1) Daenerys will NOT be happy. I believe she will go full-on Mad Queen. Finding out that she's spent years of her life believing that the Seven Kingdoms were hers by right, only to find out that according to the very same criteria which she's used to justify her ambition, she's not the rightful ruler of the Seven Kingdoms, is going to drive her over the deep end. The show will ultimately be about Jon Snow, the union of Ice and Fire, having to defeat the extremes of both Ice and Fire as represented by the Night King and Daenerys (Each side will have their own dragon. Jon Snow on Rhaegal, the Night King on Viserion, and Daenerys on Drogon).
2) He'll lose the position of King in the North and rule will pass to Sansa. She will then propose marriage and Jon will regain his position as King in the North by being Sansa's husband. And in the process he'll gain the Stark name (An old First One tradition. Great houses with only female heirs pass on the name of the daughter and not her husband). In the end Jon will forge his own identity as Jon Stark, rather than as Jon Snow, the Bastard of Winterfell, or ________, the Targaryen Prince.
3) Jon will never sit the Iron Throne, which I suspect will be destroyed by the end of the story, either by Cersei or Daenerys, both of which will be dead by the end of the story. Instead, he'll rule the North with Sansa from Winterfell, and through their children Jon and Sansa will recreate the Winterfell of their childhood memories. Bran will disappear into the wilderness permanently to take up his role as the Three-Eyed Raven, while Arya will follow in the footsteps of Nymeria and sail west of Westeros to discover whatever new lands may be there.

Err... you haven't been watching the show this whole time? It's been explained since the pilot that bastards have no inheritance rights. A trueborn son, however, has a claim to inherit lands and titles from their father. If Jon is a bastard, then it doesn't really matter who his father is. If Jon is the trueborn son of Rhaegar Targaryen, however, then he's the rightful king of the Seven Kingdoms, with a stronger claim to the Iron Throne than Daenerys.

I think that by the stories end, both Arya and Bran will end up leaving Winterfell permanently. Bran to take up his role as the Three-Eyed Raven in solitude somewhere, and Arya to follow in the footsteps of her hero, Nymeria, by traveling west in search of a new land and settling there. For those two characters, I feel like we're going to get a Frodo Baggins style end, where they're so changed by their experiences that there's no longer a place for them in their old lives, and they feel the need to move on far, far away from everyone and everything they've ever known.